Car truck



June 12, 1945.'

D. M. LIGHT CAR TRUCK FledOCt. 11, 1941 u 2 Sheets-Sheet 1 INVENTOR.

June l2, 1945. y n D M |G||1 l2,378,228

j GAR TRUCK l Filed oct. 11, 1941 sheets-sheet '2 @i @Zv Y 6.0 .fg m-f; Zag

I 13935' .dal

' INVENTOR. A Y Dam'djlligjz 144 f QQ BY i the section being taken substantially in Patented June 12, 1945` 1 invia ungut, chiaro, nl., signor aA American Steel Foundries, Chicago, Ill., a corporation o! `lflew Jersey Appleman october i1, 1941, serial N0.414,551

"s2 claims (ci. 10s-197). I

' mately in the vertical My invention relates to railway car trucks and particularly to a type of Vauch truck commonly designated quick'wheel change comprising spaced A jsidefram'es with an intervening bolster so con- .nected between said -side frames as to facilitate its temporary removal for wheel change purposes.

The general object of my invention is tedevise a novel form of such car truck utilizing bolster snubbing means housed in the columns of the side frames, said snubbing means being actu- -ated'by'means of a member associated with the bolster sometimes designated an interlocking` member. l

A specific object of my invention is to devise suchva novel car truckas that above-mentioned wherein each side frame coiuinn'maybe of general U-section with the open sidesthereoftoward each other-and each of said columns having parallel inboard` and outboard walls upon which may be mounted friction panels or wear plates for engagement with friction shoes actuwith the bolster.

My novel arrangement contemplates a snubbing structure in each 4column and with each snubbing structure may be associated resilient means independent of the bolster supporting y springs, said -resilient means being effective to urge friction shoes into engagement with friction panels on the columns.

My invention further comprehends such an arrangement as that described'wherein the friction means in each column may comprise a plurality oflwedge-shaped friction shoes and a plurality of wedge followers in frictional engagement with each other, said shoes being resiliently urged into engagement with the before-mentioned column 'K panels. y

In the drawings, Y Figure 1 is a fragmentary side elevation of a car truck embodyingmy invention, only one end of the truck being shown inasmuch as the structure is similar at opposite ends thereof.

Figure 2 is a' sectional viewof the car truck.

t hon'- zontal plane indicated by the line Z-Z-f'Figure 1. f

Figure 3 is a further sectional view through the structure of Figures 1 and 2, the section being taken substantially in the transverse vertical plane bisecting the truckl and as indicated by the line 3--3 of Figure 1.

Figure 4 is a transverse sectional view through one of the columns and the friction devices assoelated therewith, thesection being taken approxi- 4-4 of Figure 1.

Figures 5,4 5A, and 5B show the detail of 'my novel form of follower plate o r interlocking member, Figure 5 being a fragmentary top plan view thereof, Figure 5A an edge elevation taken from the bottom as seen in Figure 5.and Figure 5B a transverse sectional view taken substantially in the plane indicated by the line B.-l 3 of Figure 5. l v

Figures 8, 6A, and 6B show the detail of my agel form of friction device top follower, Fig- 6 being. a top. plan view thereof, Figure 6A a side elevation taken from the bottom as seen in ated by the before-mentioned member associated -V Figure 6 and Figure 6B an end view taken from,

the right as seen in Figure 6. A

Figures 7, 7A, and '7B illustrate my novel form of friction device side wedge, Figure 7 `being 'a plan view taken fromthe inner face thereof, Figure 'IA a side elevation, and Figure '1B an end view.

My novel Structure comprises a. truss type side frame having .a compression member 2,a tension member 4, and spaced integral columns 6, 8

defining with said members a central bolster opening 8 and a window opening I0 lat ,each side.

thereof. Above the bolster opening -8 the compression member may have a general box-section as best seen at l2 in Figure 3 and below said bolster opening the tension member 4 may be of box-section with the bottom chord I4, inboard and outboard walls I6 and 18, and a top .chord 20 widened and formed with inboard and outboard upstanding anges 22 and 2'4 defining a spring'seat 2B upon which may be positioned a plurality of bolster supporting springs diagrammatically` indicated at 28, 28, saidsprings 'being positioned with respect to said seat as by means of upstanding lugs 30, 30. The upper 'ends of the springs 28, 28 may be confined by a spring plate 32 upon which may be seated in usual manner the end of the .bolster generally designated 34. The bolster 34 may have an end portion of general box-section comprising the top wall 3B and the bottom wall38 reinforced by the vertical intermediate wall 40 and the bolster end may have at each side thereof a vertical guide Llug 42 in engagement .with a complementary channel 44 formed on the bracket 46 Awhich may be an integral part of theA adjacentcolumnand positioned on the inboard face thereof intermediate y the length of the column as best seen in the v'iew of Figure 3. l'I'he bracket 46 may be of limiteddepth and the upper end thereof may be spaced lfrom the bottom web of the compression member theref piene mdicafedby the uneA web 52 of the column.

pver a distance A as indicated in Figure 3, said distance being of such depth as to permit the withdrawal of the bolster from the bolster opening by elevation thereof for disengagement of the bolster guide lug from the before-mentioned channel of the bracket 46.

Each column 6 may have a substantial U-section throughout its length with the inboard wall 48, the outboard wall 50 and the transverse webr 52 as best illustrated in the view of Figure 2. 0n the inner faces of each column may be secured by any convenient means as by welding as at 54, 54 inboard and outboard angle wear plates 56 and B, and the lower ends of said wear plates may conveniently abutl as at -59 the horizontal ledge 6| formed on the before-mentioned transverse Housed within each column may be a friction device comprising a top follower 60 presenting on its bottom face at oppositesides thereof spaced .wedge-shaped friction surfaces for engagement as at 62, 62 with complementary surfaces formed on inboard and outboard friction shoes 64, 64. Each Vfriction shoe 64 is symmetrical in form and the V-shaped friction surface at the bottom edge thereofmay have engagement as at 06 with the complementary face formed on the bottom follower 68, said bottom follower 68 being an integral part of the follower plate or interlocking member generally designated 10 and shown in detail in'Figures 5, 5A, and 5B. The interlocking member Ai0 comprises a relatively wide central.

plate portion 12 merging at each end with a follower end portion generally designated 68, the juncture of said end portion and said plate portion being reinforced by a vertical rib 14. The combination interlocking member and follower plate 10 may be recessed in the bottom wall 38 of the bolster as best seen in the sectional view of Figure 3 and the member 10 may be secured to the bolster as at 16 (Figure 1) by the upstanding lug 18 centrally formed on the member 10, said lug" 18 projecting through the bottom wall 38 of the Ybolster centrally thereof, and the intermediate wall 40 of said bolster being cored away to accommodate said lug. 'A cotter key or other forms of securing means may extend through the y lug 18 as indicated at 80 (Figure l) thus preventing accidental dismantling of said bolster from said follower plate. Each` side wall of the bolster may also be cored away as at 82 (Figure l) to t accommodate the rib 14 reinforcing the juncture the lower edges of the friction shoes 64, 64 as already referred to. Each end follower portion 88 is formed with a vertical bolt opening |00 for the purpose already described.

-The detail of the tcp follower is shown in Figures 6, 6A, and 6B. It will be noted that the follower 60 is bisectionai in form having at each end thereof a wedge-shaped friction surface |02 for engagement with a complementary V-shaped surface |04` on the adjacent friction shoe 64. Each follower 60 may be perforated centrally thereof to define the bolt hole |06 and a rectangular recess |08 may be formed in the top wall thereof for convenient accommodation of the retaining bolt 86.

The detail of each friction shoe 64 is shown in Figures '7, 7A, and 7B. The V-shaped tapering friction surfaces |04, |04 at opposite ends thereof are clearly apparent from the views of these figures. y

It will be readily apparent that the bolster 34 may be disengaged from the side frame by disconnecting therefrom the follower plate and interlocking member 10 by removal of the cotter means at after which the bolster 34 may be elevated until the guide lug 42 at the side thereof is disengaged from the vertical slot 44 in the side frame bracket 46 after-which the bolster may be withdrawn from the bolster opening of the side frame. This operation may becarried out, of course, without disturbing the friction devices in the columns or the spring group upon which the bolster may normally be seated.

When the bolster is in normal operative position, vertical movements thereof will be snubbed or restricted by the friction developed through the friction means in` their respective columns, said friction means being operated by the follower plate 10 forming a part thereof. It will be understood that the amount of friction developed may be modified by the degree of taper afforded on the complementary friction surfaces on the shoes and followers as well as by the connection of the resilient means at 08 which' forma part of said. friction devices.

It is to be understood that I do-not wish to be limited by the exact embodiment of the device shown which is merely by way of illustration and of the end and plate portions of the interlocking member.

The top and bottom followers 60 and 68 of the friction ldevice may be cored out centrally thereof to accommodate a retaining bolt 86 which may project below the follower portion 68 for support.

of the coil spring 88, the top end of said -spring being afforded a seat as at against the follower member 68, and the bottom end thereof abutting the spring seat 92 which may be retained in position by means of the double nut 84 threaded on ithe end of the bolt 86. In the view of Figure 4,

the coil spring 8 8 is diagrammatically indicated to simplify the showing thereof.

' As already mentioned, the detail of the 4combination follower plate and interlocking member 'l0 is shown in Figures 5..; 5A, and 5B. It may be noted that each follower end member 6B is formed with V-shaped tapering friction surfaces 96, 06

`adjacent the plate portion `'Iii and at the opposite side-thereof similar V-shaped tapering friction surfaces 98, 08, said surfaces 95 and 88 engaging similar and complementary friction surfaces on not limitation as various and other forms of. the

device will, of course, be apparent to those skilled in the art without departing from the spirit of the invention or the scope ofthe claims.

I claim:

l. In a railway car truck, a side frame having tension fand compression members and-integral columns defining therewith a central bolsterl opening, each of said columns having a U-section with transverse webs at the remote` sides thereof,

inboard and outboard walls, wear plates on said walls, springs on said tensio member in said opening, a bolster seated on sa d springs, a member secured to said bolster-and having end portions housed within respective columns for association with friction devicestherein, each of said f end portions comprising a bottom follower, a top follower spaced therefrom, friction shoes between said followers, resilient means urging said fric-` tion shoes intovengagement'with said followers and into engagement with said wear plates, and means extending through said followers and securing said resilient means against one of said followers, bolster guide brackets on the inboard faces of each of said columns, and bolster guide lugs on the oppositev walls of said bolster in engagement with said brackets, said brackets having al vertical clearance from the bottom web of the compresion member thereover at, least equal to the vertical depth of said guide lugs to permit dismantling of said bolster at the top of said Opening.

` 2. In a railway car truck, a side frame having tension and' compression members and ln tegral columns defining therewith a central bolw ster opening, each of said columns having. a. U-

section with transverse webs at the remote sides thereof,inboardand outboard' walls, wear plates on said walls, springs on said tension member in member secured to `said bolster and having end portions housed within respective columns for association with friction devices therein, each of said end portions comprising abottom follower, a top follower spaced therefrom, friction shoes between said followers, resilient means urging said friction shoes into engagement with said 'followers and into engagement with said wear plates, bolster guide brackets on the inboard faces of eachaof said columns, and bolster guide lugs on the opposite walls of said bolster in engagement with said brackets, said brackets having a. vertical clearance from the bottomweb of the compression member thereover at least equal to i the vertical depth of said guide lugs to permit distion with transverse webs at the remote sides thereof, inboard and outboard'walls, wear plates on said walls, springs on said tension member in said opening, a bolsterseated on said springs, a member secured to said bolster and having end portions housed within respective columns for,

lassociation with friction devices therein, each .of said end portions comprising a bottom-follower, a top follower spaced therefrom, friction shoes btween said followers, resilient means urging said friction shoes intoy engagement with said followers and `into engagement. with said wear plates, and means extending through said' vsaid opening, a bolster seated on said springs, a

said springs, an interlocking memberrecessed in the bottom wall of said bolster with end portions extending into said columns respectlvely, each of said end portions comprising a bottom follower of a friction device housed in the adjacent column, each of vsaid friction devices having a spaced follower, friction shoes each having frictional engagement with both followers and one of said legs, spring means associated with each of said devices for urging 'said shoes into engagement with said followers and said legs, and securing means extending through saidA followers and retaining said spring means against one of said followers.

6. In a.' railway car truck, a side frame having spaced columns defining in part a central bolster opening, each column comprising inboard and outboard legs, a tension member beneath said opening, springs on said tension member in said opening. Aa bolster end extending into said opening and seated on said springsfan interlocking member recessed in the bottom wall of said bolster with end portions housed in said columns respectively, each of said en d portions comprising a bottom follower of a friction device in the adjacent column, each of said friction devices comprising a spaced follower, a plurality of friction shoes having frictional engagementv with both followers and respective legs, and spring means associated with eachof said devices for. urging' means for said spring means.

'1; In a-railway car truck, a side frzme having tension and compression members and spaced columns deflning a bolster opening, springs on said` tension member in saidfopening, a bolster followers and securing said resilient means against one of said followers.

4.5 In a railway car truck, a. side frame having tension and compressionmembers and spaced columns deiningigl bolster openingl springs on' said tension member in said opening, a. bolster on said springs, a member recessed in the bottom of said bolster with end portions housed in re' spective columns, each of said end portions comprising a follower lassociated with a. friction device housed in the adjacent column, 'each of said friction devices comprising a spaced follower,

. spaced friction shoes each havingdiagonal face engagement with both of said `followers, said shoesvhavin'g frictional engagement respectively with'spaced walls of the adjacent' column, resilient means urging said shoes and followers into "opening, each column comprising spaced legs a tension member beneath said opening, springs on said tension member in said opening, a. bolster. end extending into said opening and seated on on said springs, a member recessed in the bottom of said bolster with end portions housed in respective columns, each of said end portions comprising a follower associated with a friction device housed in the adjacent column, each of said friction devices comprising a spaced follower, spaced friction shoes each having diagonal face n engagement with both of said followers, and resilient means urging said shoes and followers in'- to engagement wiht each other and urging said shoes into engagement with spaced walls of the adjacent column. f

8. In a railway car truck, a side frame having tension and compressionV members and integral columns defining therewith a. central bolster opening, each of said columns having a U-section with transverse webs at the remote sides thereof.

inboard and outboard walls, wear plates on said walls, springs on said tension memberfin said opening, abolster seated on said springs, a mem'- ber secured to said bolster and havinglend por tions housed within respectivecolumns for asso- A ciation with frictiondevices therein, each of said end portions comprising a bo toni follower, a top follower spaced therefrom, friction shoes between said followers, and resilient means urging said friction shoes into engagement` with said followers and into engagement with said wear plates.

9. In a railway car truck, a side frame having tension 'and compression members land spaced columns defining a bolster opening, each of said with end portions housed in said columns respectively. each of said end portions forming a follower associated with afriction device in the adjacent column, each of said friction' devices comprisingl a spaced follower and friction shoes between saidl followers engaging said surfaces, and means urging said shoes and said followers into engagement with each other, said last-mentioned means comprising a coil spring and means securing said coil spring against one of said followers.

lo'. In a railway car truck, a truss side frame having tension and compression members and spaced columns defining a bolster opening, each of said columns having a U-section with trans.r verse webs at the remote sides of respective columns, bolster supporting springs on said tension member in said opening, a bolster ,supported on said springs, an interlocking member recessed in the bottom wall of said 'bolster andhaving end portions defining bottom followers of friction devices housed in the respectivecolumns, each of said friction devices comprising a top follower, friction shoes in engagement with said followers and in frlctional engagement with the adjacent column walls, and resilient means for urging said shoes and followers into engagement with each other.

11. In arailway car truck, a side frame having spaced columns defining in part a central bolster opening, each column having spaced legs, a ten-1 sion member beneath said opening, springs on said tension member in said opening, a bolster end extending into said opening and seated on said springs, an interlocking member recessed in the bottom wall of said bolster with end portions housed in said columns respectively, each of said lend portions comprising a. bottom follower of a friction device in the adjacent column, each of said friction devices comprising a spaced follower, a plurality of friction shoes engaged with re-` spective legs and having V- shaped tapering frictional engagement with both followers, and spring means associated with each of said devices for urging said shoes into engagement with said followers and said legs.

12. In a railway cartruck, a side frame having spaced columns dening in part a central bolster opening, atension member beneath said opening,

springs on said tension member in said opening, a bolster end extending into said opening and seated on said springs, an interlocking member recessed in the bottom wall of said bolster'with end portionsl housed in said columns respectively,

each of said end portions comprising a bottom follower of a friction device in the adjacent column, and each of said friction devices comprising a spaced follower and friction shoes engaging said followers and spaced walls of the associated colwith end portions housed in said columns respectively, each of said end portions forming a follower associated with a friction device vin the adjacent column, each of said friction devices comprising aspaced follower and friction shoes between said followers engaging said surfaces, and means urging said shoes and said followers into engagement witheach other.

15 In a railway car truck, a side frame having tension and compression ,members and spaced columns defining a bolster opening, 'each of said columns having inboard and outboard walls, friction surfaces on said walls, a bolster extending into said opening, a member xed to said bolster with end portions housed in said columns respectively, each of saidend portions forming a fol- 1ower associated with e friction device in the adjacent column, each of said friction devices comprising a spaced follower and friction shoes between said followers engaging said surfaces.

16. In a railway car truck, a side frame hav.- ing tension and compression members and spaced columns dening a bolster opening, springs on said tension member in saidv opening, a bolster on said springs, a member recessed in the bottomof said bolster with end portions housed in respective columns, each of said end portions comprising a follower associated with a friction device housed in the adjacent column, each of said friction devices comprising a spaced follower, and friction shoesin engagement with1 respective walls of the `adjacent column, each of said shoes having diagumn, and resilient meansurging said shoes and y followers into engagement with each other.

13. In a railway car truck, a side frame having spaced columns defining in part a central bolster opening, each column comprising spaced legs, a tension member beneath said opening, springs on said tension member in said opening, a bolster end extending into said opening and seated on said springs, an interlocking member recessed in the bottomA wall of said bolster with end portions housed in said columns respectively, eac of said end portions comprising a bottom folio er of a friction device in the adjacent column, 'a d each of said friction devices comprising a spa ed follower and friction shoes engaging saidfollowers and respective legs.

14. In a. railway car truck, a side frame having tension and compression members and spaced columns defining a bolster opening, each of said tionv surfaces onj'said walls, a bolster extending into said opening, a member fixed to said bolster onal face engagement with both of said followers; 17. In a railway car truck, a side framehaving spaced columns and an intervening bolster open,- ing',r a bolster resiliently supported within said opening, inboard and outboard friction surfaces within each column, and friction means associated with each column and comprising awedge unit consisting of a wedge element vertically movable with Athe bolster and disposed between the spaced friction surfaces within said column, a wedge unit consisting of wedge elements ,in frictional engagement with respective surfaces and in complementary wedge engagement with the first-mentioned element, resilient means under compression and spaced from one of said units and seated against the other thereof, a rigidmember extending vthrough said other unit and through said resilient means and carrying abutment means therefor, and a connection between said rigid member and the wedge unit remote from said resilient means.

18. In a railway car truck, a side frame having spaced columns and an intervening bolster opening, a bolster. resiliently supported within said opening, and a friction device associated with each of said columns and comprising'inboard and outboard friction surfaces therein, Wedge means comprising a wedge element associated with the bolster and vertically movable therewith, said element being disposed intermediate said surfaces,

additionalwedge means comprising wedge elements in frictionalengagement with respective surfaces and in wedge engagement with saidvnrst- `mentioned. element, resilient means compressed v j against'one of said wedge means and spaced from icolumns having inboard and outboard walls, fricthe other wedge means, and means for transmitting reaction of said resilient means to said other wedge means.

19. In a railway car truck, a side frame'v having spaced columns and an intervening bolster opening, a, bolster 'resiliently supported within said l, opening, and a. friction device associated. with e' each of said columns and comprising inboard and outboard friction'surfaces therein, a wedge element associated with the bolster and vertically movable therewith, said element being disposed intermediate said surfaces, spaced friction means in frictional engagement with respective surfaces and in wedge engagement with said element, and resilient means including a compressed spring operatively connected at its opposite ends respectively to said element andy said friction means for urging the latter into said engagement.

20. In a railway car truck, a side frame comprising spaced columns and an intervening bolster opening, inboard and outboard friction surf faces on each column, friction elements engaged therewith, a bolster in said opening and resiliently supported from said frame, a member fixed to2 -said bolster, and means carried by said member for actuating said elements during relative movement between said bolster and said frame, said means comprising Wedge means in complementary wedge engagement with said elements wedge means and said bolster, said connection beand resilient means operatively associated with comprising friction faces on said member engaging the elements associatedwith each column, said faces tapering toward respective of the friction surfaces on said column, resilient means compressed against said member, and means operatively connected to said resilient means and to said elements for transmitting reaction of said resilient means thereto, whereby said elements are urged into engagement with the associated faces and surfaces. i

22. In a railway car truck, a side frame comprising spaced columns and an intervening bol- Y ster opening, inboard and outboard friction surfaces on each column, friction elements engaged therewith, a bolster'in s aid opening and resiliently supported from said frame, a member xed to said bolster, means carried by said member for actuating said elements during relative movement between said bolster and said frame, said means comprising wedge surfaces on said member, a.

spring compressed against a portion of said'member remote from saidelements, and means operatively connected to said spring and to said elements for transmitting reaction of said spring thereto, whereby said elements are urged into engagement with the associated wedge and column surfaces.

23. In a railway car truck, aside'frame comprising spaced columns and an intervening bolster opening, each column comprising spaced walls, a spring group on said frame in said opening, a bolster supported on said group and a friction device in each column comprising friction shoes engaging respective walls, spaced wedge means engaged with said shoes, one of said wedge means being interlocked with the bolster, and resilient means urging said shoes and said Wedge means into engagement.

24. In a railway car truck', a side frame comprising spaced columns and an intervening bolster opening, a bolster .in said opening resiiientiy supported from said frame, each column comprising spaced walls, friction shoes engaging said walls, wedge means engaging said shoes, resilient means engaged with said wedge means and operative to urge said shoes into engagement with said walls, and an interlocking Vconnection between l said wedge means and ,said bolster.

25. In a railway car truck, a side frame comprising spaced columns and an intervening bolster opening, a bolster insaid opening resiliently sup- 'ported from said frame, each column comprising 3 spaced walls, friction shoes engaging said walls,

wedge means engaging said shoes, resilient means engaged with said wedge, meansand operative to urge said shoes into engagement with said walls, and 'an interlocking connection between said ing thesole means affording actuation of said shoes bysaid bolster.

26. kIn ya'railway car truck, a side frame comprising spaced columns and an intervening bolster opening, a bolster in said opening resiliently supported from said frame, each column comprising spaced walls, friction shoes engaging said walls, wedge means engaging said shoes, resilient means.

engaged with said wedge means and operati-ve to urge said shoes into engagement with said walls, and an interlocking connection between said wedge means and said bolster, said resilient means being spaced from said frame.

27. In a railway car truck, a side frame comprising spaced columns and an intervening bolster opening, each column having inboard and outboard walls, a bolster .in said bolster opening and resiliently supported from said frame, and a friction device in each column comprising frictionc shoes engaging the spaced` walls thereof, spaced wedge means engaging said shoes, and resilient means urging said wedgeneans into engagement with said shoes, whereby said shoes are A urged into engagement with said walls, and an operative connection between `each device and said bolster. 28. In a railway car truck, a side frame comprising spaced columns and Y iently supported from device in each column engaging the spaced'walls thereof, spaced wedge engaging said shoes, resilient means engaging one of said wedge means, and means extending through said resilient means and consaid frame, and a friction nected to the otherof said wedge means, oneI of said wedge means being rigidlyv associated with and vertically movable with said bolster.

29. In an interlocking member for a railway car truck, an

wedge surfaces thereof.

3 0. In a railway car truck, a side frame having spaced columns and an intervening bolster opening, a bolster resiliently supported in said opencomprising friction shoes reaction of said resilient means to said shoes.

31. 1n a railway car truck, a side frame having spaced columns and an intervening bolster opening,- a bolster resiliently supported in said opening, and friction means comprising,r spaced friction surfaces on said frame, wedge surfaces vertically movable with said bolster, friction shoes each engaging one of said wedge and one of said friction surfaces, an abutment surface vertically movable .with said bolster, resilient means compressed at its upper end against said abutment surface, and a bolt and nut assembly operatively connected to said resilient means and said shoes for transmitting reaction of said resilient means to said shoes, said resilient means being sleeved over said bolt and nut assembly intermediate the ends thereof.

32. In a railway car truck, a side frame having spaced columns and an intervening bolster opening, a bolster resiliently supported in said opening, and friction means comprising oppositely spaced substantially parallel friction surfaces on said frame, spaced wedge surfaces in fixed relationship with respect to said bolster and vertically movable therewith, a pair of friction shoes engaging respective friction surfaces and' respective wedge surfaces, an abutment surface in fixed relationship with respect to said bolster and vertically movable therewith, resilient means compressed against said surface, and a bolt and nut assembly operatively connected to said resilient means and both of said shoes for transmitting reaction of said resilient means to said shoes.

DAVID M. LIGHT. 

